Within the field of jetting droplets of viscous medium onto a substrate, particularly solder paste onto an electronic circuit board, there is an increased desire to perform the actual jetting “on the fly”, i.e. with relative movement between the substrate and the jetting device during jetting and without stopping for each location on the substrate where viscous medium is to be deposited, in order to increase the manufacturing speed of electronic circuit boards.
A further means for improving the manufacturing speed of electronic circuit boards is to provide reduced idle time of the manufacturing line. One way of doing this is disclosed in the co-pending International patent application published under WO 00/61297, which discloses an exchangeable assembly for jetting droplets of viscous medium onto a substrate and is incorporated herein by reference. As evident from said application, such an assembly, inter alia, improves the flexibility and reduces the idle time of a jetting apparatus.
Due to the high quality requirements of the electronic industry and the detrimental consequences of error prone circuit boards, a high degree of accuracy and reproducibility is required, along with a high level of flexibility. This requirement is even further accentuated by the increased speed at which a substrate is provided with viscous medium.